Cooperative Intelligent Transport Systems (C-ITS) are systems that utilize Information and Communications Technology (ICT) to support improved safety and more efficient usage of the transportation infrastructure for transport of goods and humans over any transportation mean.
Intelligent Transport Systems (ITS) services, protocols and connectivity solutions are described in specifications issued by standardization bodies like IEEE, SAE, ETSI and ISO. Besides in the mentioned standards, the C-ITS system architecture is elaborated in research collaborations like COmmunication Network VEhicle Road Global Extension (CONVERGE), Nordic Way and in consortiums of automobile manufacturers, suppliers and research organizations like ERTICO and Car-2-Car Communication Consortium.
There is an ongoing discussion regarding connectivity for C-ITS. The discussion is about whether the ETSI ITS G5/IEEE WAVE DSRC solutions, cellular 3rd Generation Partnership Project (3GPP) technologies, or a new 3GPP based Long-Term Evolution (LTE) Vehicle-to-anything (V2X) radio solutions should be used, and in what combinations (e.g. hybrid solutions). C-ITS is based on a frequent short-range communication between different stations or units, mobile or stationary, exchanging e.g. information ranging from position, velocity, environmental conditions, traffic situation etc. When many vehicles are present in a limited area and/or when external conditions are cumbersome, the signaling load becomes large and congestion problems may arise.
Vehicles are getting connected to mobile networks. They are using Telematic Control Units (TCUs) located in vehicles, (normally) integrated in the vehicle electronical system or connected via an external interface such as the On Board Diagnostics II (OBD II) interface. They are equipped with a radio for communicating via a cellular network with an application server. The application server is under the control of e.g. the vehicle Original Equipment Manufacturer (OEM) or another 3rd party service supplier. In addition the TCU might have radios for short range communication, e.g. Dedicated Short-Range Communications (DSRC) or in the future LTE technology (LTE-V) might be used for the short range communication.
The TCU is sometimes also referred to as a Telematics Module (TEM) or an On Board Unit (OBU).
Being integrated or connected to the vehicles external interface means that the TCU can receive events from the vehicle system, forward this to the OEM, forward information to other vehicles or road side equipment using the short range communication or to forward the information to road traffic authorities using the cellular network. The TCU can of course also receive information on the short range radio or from the cellular network and display or forward that information. E.g. a wheel that loses the grip can be detected by the vehicle system and a slippery road warning can be distributed with a broadcast message on the short range radio or sent to a central entity for evaluation. Alternatively, the received information can be acted upon by the vehicle, e.g. a received message about slippery road can activate the anti-spin system of the vehicle.
There is a feature in mobile networks to allow devices to go into extended sleep mode, extended discontinuous reception (eDRX). The length of the sleep mode can be proposed by the device, current maximum sleep time is 2.9 hours. The eDRX feature is controlled by sending information during the attach procedure and the Tracking Area update procedure.
Even though a car is equipped with a powerful battery, there are several systems in the car that consumes power, e.g. alarm, computers, etc. A vehicle might also be parked for a long time, e.g. before shipping to customer, at an airport etc. so there is a need to optimize the battery usage.